Rack and pinion operating means for enclosed circuit disconnect devices with snap action and positive kickoff features

ABSTRACT

A rack and pinion stored energy handle operator mounted to an enclosure body to provide snap-action actuation of a knife switch within the enclosure. Resistance of the switch contacts to fully engage or disengage is overcome by separate positive drive features which automatically couple the movable contact structure directly to the handle. A modification eliminates the stored energy feature to permit the same basic operator to control an automatic circuit breaker having built-in snap-action, the modified operator having a shock absorbing feature to prevent damage to the circuit breaker handle under adverse operation.

United States Patent IIII Inventors Allan P. Charhonneau [56] References Cited wflmw; UNITED STATES PATENTS A I No ga 1,600,127 9/1920 Nero 200/78 lf Se 968 2,242,167 5/1941 Bentley m1. 200/78 P p 2,368,083 1/1945 Adam ..200/l53(.16)X

atented Feb. 9, 1971 Assi nee Cu'kbfl Inc 2,428,832 10/1947 Charbonneau 200/70 3 Milwaukee 2,870,282 1/1959 Brand ZOO/67(PKS) co 1 Mbehwm 3,002,068 9/1961 Maier 200/ 153(.7)UX 3,296,393 1/1967 Rimmer et a1. 200/50(.1) 3,469,042 9/1969 Sandor ..200/153(.16)UX Primary ExaminerRobert S Macon Assistant ExaminerRobert A. Vanderhye Attorney-Hugh R. Rather RACK AND PINION OPERATING MEANS FOR ENCLOSED CIRCUIT DISCONNECT DEVICES ABSTRACT: A rack and p1n1on stored energy handle opera- ACTION AND POSITIVE KICKOFF tor mounted to an enclosure body to provide snap-action ac- 5 Claim Dr in F tuation of a knife switch within the enclosure. Resistance of aw g the switch contacts to fully engage or disengage is overcome U.S. Cl...., 200/153, by separate positive drive features which automatically couple 200/70, 200/67; 74/29 the movable contact structure directly to the handle. Int. Cl H0lh 3/40, A modification eliminates the stored energy feature to per- H01h 5/06 mit the same basic operator to control an automatic circuit Field of Search ..200/153.16, breaker having built-in snap-action, the modified operator 153.20, 154, 6715, 67PKS, 68 (Cursory), 70, 77, having a shock absorbing feature to prevent damage to the cir- 78; 74/29 (Cursory), 422, 120 cuit breaker handle under adverse operation.

4 2d EC 255 2 9o M g 2e fsz za 50a fig 20a 2/1 I l L w m PATENTEU FEB 9 19m 3562 463 sum 2 m e PATENTEU FEB 9 I97! SHEET h BF 6 PATENTEU FEB 91971 3,562,463

sum 5 BF 6 PATENTED FEB 919m sum 6 or 6 RACK AND PIN'ION OPERATING MEANS FOR ENCLOSED CIRCUIT DISCONNECT DEVICES WITH SNAP ACTION AND POSITIVE KICKOFF FEATURES BACKGROUND OF THE INVENTION This invention relates to enclosed circuit disconnect and protective devices, and more particularly to enclosure mounted external operators therefor.

Enclosed circuit disconnect and protective devices are provided in a wide variety of motor control applications ranging from individual enclosures to switchboard and unitized motor control centers. The enclosed devices may be of the automatic circuit breaker or fused knife switch type which may or may not have built-in quick make and break operation and whose physical size varies with the electrical capacity of the motors to be controlled.

Manufacturers offering a complete line of motor control equipment find it desirable from economic and appearance viewpoints to provide external operator mechanisms of one general and closely similar construction to meet all enclosed disconnect device applications. The operators of such general construction must provide snap'action mechanism for those disconnect devices which do not include this action, and must have an operational throw which can be readily matched to the throw of each of the large variety of types and sizes of devices to be actuated. The operators must further include positive drive and interlock features which will accommodate the wide variety of operating characteristics found in the numerous disconnect device applications.

SUMMARY OF THE INVENTION An operator mechanism for enclosed circuit disconnect and protective devices is provided in this invention which, according to present design practices, mounts directly to a body portion of the enclosure to maintain the operator mechanism in full control of the enclosed device at all times, regardless of the position of the enclosure cover or door. Movement of the external handle affects linear movement of the internal mechanism to which is rigidly attached a drive link for actuating the enclosed device. The internal mechanism movement may be direct with the handle, or snap-action by virtue of a stored energy arrangement within the mechanism. A first positive drive linkage places the last increment of contact movement in the ON direction under direct control of the handle and a second positive drive linkage places the initial increment of contact movement in the OFF direction under direct control of the handle if the contacts do not fully engage or resist disengagement.

It is therefor a primary object of this invention to provide an operator mechanism for enclosed circuit disconnect and protective devices which, through minor modifications, is suitable for operating different types of such devices in a wide variety of sizes and applications.

It is a further object of this invention to provide a stored energy snap-action operator mechanism for enclosed circuit disconnect and protective devices which has a positive drive linkage in the circuit making direction which is rendered effective when the mechanism fails to traverse its total travel.

It is still a further object of this invention to provide a stored energy snap-action operator mechanism for enclosed circuit disconnect and protective devices which has a positive drive connection in the circuit breaking direction which is rendered effective upon failure of the mechanism to separate the contacts of the device.

These and other objects will become more readily apparent in the following specification and claims when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of the operator mechanism of this invention shown in a switch OFF operating position;

FIG. 2 is a view similar to FIG. 1 with certain exterior portions broken away to illustrate the internal mechanism of the operator;

FIG. 3 is a cross-sectional view of the operator mechanism taken generally along the line 3-3 of FIG. 1 and drawn to an enlarged scale;

FIG. 4 is a longitudinal sectional view of the operator mechanism taken generally along the line 44 of FIG. 1;

FIG. 5 is a view similar to FIG. 1 with an exterior side member removed and showing the mechanism partly displaced toward a switch ON operating position;

FIG. 6 is a view similar to FIG. 5 but drawn to a reduced scale and showing the operator mechanism fully displaced to the switch ON operating position;

FIG. 7 is a view similar to FIG. 6 showing the operator mechanism partly displaced from the switch 0N operating position of FIG. 6 toward the switch OFF operating position of FIG. 1;

FIG. 8 is a side elevational view of the operator mechanism in the switch ON operating position drawn to a reduced scale and showing a positive drive feature of the mechanism;

FIG. 9 is an exploded isometric view of a lower portion of the operator mechanism;

FIGS. 10 and 11 are side elevational views of the opposite side of the operator mechanism of FIG. I, drawn to a reduced scale, together with fragmentary showings of an enclosure and broken line showings of an electrical switch, the two views depicting the switch OFF and switch ON operating positions, respectively;

FIG. 12 is a side elevational view of a modified version of the operator mechanism of this invention shown in an OFF position;

FIG. 13 is a fragmentary right-end elevational view of the operator mechanism of FIG. 12; and

FIG. 14 is a longitudinal sectional view taken along line 14-14 of FIG. 12.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, and particularly FIGS. 1 and 2 thereof, the operator mechanism is shown to be constructed principally upon a die cast housing 2. The housing 2 comprises a generally rectangular flat base 20, a raised elongated boss 2b and an upstanding hollow gear box portion 2c which is open to the lower side of the base 2a as viewed in the drawings.

An operator handle assembly is journaled for rotation in the portion 2c of housing 2. The handle assembly comprises a pair of levers 4, one of which has a flatted shaft 6 rigidly secured thereto to extend transversely through the housing portion 20. The other lever member 4 has a collar rigidly secured thereto, the collar being provided with a central opening through which the end of shaft 6 may extend to be riveted over or otherwise permanently secured to the collar. The joint between the collar and shaft are ground smooth after riveting to obscure the joint for appearance purposes. An insulating handle member 8 is secured to the free ends of levers 4 by a screw 10 which takes into a hexagonal nut 12 (FIGS. 10 and l 1 Housing 2 is provided with redundant upstanding central ribs 2d and 2e which extend longitudinally of the housing to either side of the portion 2c. The left-hand rib 2d as viewed in FIG. 2 has an elongated opening 2f formed therein. The levers 4 of the handle assembly are also provided with similar elongated and aligned openings 4a which are aligned with the opening 2f in the switch OFF position of the operator mechanism. The aligned openings 2f and 4a permit the insertion of as many as three padlock hasps therethrough to lock the mechanism in the OFF position. The right-hand rib 2e as viewed in FIG. 2 is provided with a drill point depression 23 to facilitate drilling a clearance hole for a single padlock hasp if it is desired to lock the mechanism in the switch ON position thereof.

The flatted portion of shaft 6 within the hollow portion 2c of housing 2 carries a correspondingly apertured spur gear 14 to provide a rotationally keyed assembly. An idler gear 16, indentical to spur gear 14, is mounted in mesh with gear 14 within the housing portion 20 by a bearing 18. The gears 14 and 16, in addition to the elongated central aperture corresponding to the shaft 6, further have a superimposed circular central aperture of a diameter greater than the narrow dimension of the elongated aperture, the circular aperture corresponding to the diameter of bearing 18 to permit the gears to be used in either location. Bearing 18 has axial extensions which fit within slots (not shown) in the inner sidewalls of housing portion 20, the slots being open to the bottom surface of the housing. A plate 20 having an opening 20a for idler gear 16 is secured over the open side of housing 2 by a pair of screws 22 (FIG. 2) to trap the axial extensions of bearing 18 against the upper ends of the slots, thereby mounting the idler gear within the housing.

Housing 2 further has a pair of substantially rectangular bosses 2h depending from the opposite ends of base portion 20 thereof. A pair of flat, rectangular side places 24 and 26 are secured at their upper corners to the opposite sides of bosses 2!: by a pair of rivets 28 which pass through aligned openings in the plates and rectangular bosses. The lower corners of side plates 24 and 26 are secured in spaced apart relation by a pair of rivets 30 which pass through aligned holes in the plates and through spacer sleeves 32 which abut the inner faces of plates 24 and 26 to maintain the plates in parallel relation.

A rack assembly is mounted for longitudinal movement between the side plates 24 and 26 adjacent the housing 2. With particular reference to FIG. 9, the rack assembly comprises a toothed rack 34 and a pair of side pieces '36 and 38 secured together by a pair of rivets 40 which pass through pairs of aligned holes 340, 36a and 38a in the respective members. Each of the members of the rack assembly further have second pairs of aligned holes 34b, 36b and 38b, respectively, into which a pair of axle pins 42 are inserted to extend beyond the opposite sides of the assembly. Axle pins 42 have reduced outer end portions over which are disposed four rollers 44 which are also provided with reduced diameter outer portions. Side plates 24 and 26 are each provided with a pairs of Iongitudinally aligned spaced elongated slots 24a and 26a, respectively, the slots 24a being in corresponding transverse alignment with the slots 26a. The reduced diameter outer portions of rollers 44 extend within the respective slots 24a and 26a to mount the rack assembly for longitudinal movement between the side plates within the limits of the slots 24a and 26a. The larger diameter portions of rollers 44 lie between the rack assembly and the inner faces of side plates 24 and 26 to space the rack assembly centrally between the plates (see FIG. 3). It may be seen in FIG. 2 that the teeth of rack 34 are in mesh with idler gear 16 to cause the linear movement of the rack assembly to be under the direct control of the handle assembly.

A leaf spring detent arrangement is provided in the snap-action version of the mechanism to urge the handle to remain in its switch ON operation position. As seen best in FIG. 2, a plurality of stacked leaf springs 46 are secured to the underside of the right-hand boss 2): by a screw 48. Springs 46 extend inwardly of the mechanism and terminate in inverted V-shaped ends which are laterally offset toward the side plate 26 (FIG. 3). The underside of rack 34 has the opposite lower corners thereof beveled to afford a camming surface for the ends of springs 46 and has a shallow inverted V-shaped groove 34c located intermediate its opposite ends and offset to one side to be in longitudinal alignment with the ends of springs 46. Movement of the rack assembly from its left-hand, or switch OFF, operating position (FIG. 2) in response to corresponding movement of the handle cams the inner ends of spring 46 downwardly. The apex of the upper spring 46 bears against the underside of rack 34 until the rack completes its travel, at which time the terminating end formation of detent springs 46 extend within the slot 340 and bear against the right-hand sloped surface thereof. To return the rack assembly to the lefthand switch OFF position, sufiicient force must be applied to the handle to cam the detent spring assembly out of the groove 340 of rack 34.

It is commonly desirable in enclosed circuit disconnect applications to provide an interlocking function between the door or cover of the enclosure and the handle of the operator mechanism to prevent both closing the circuit while the door is open and opening the door while the circuit is closed. The doors of these enclosures are provided with separate closure latches, handles and interlocking members which include portions that cooperate with an interlock lever of the operator. Insofar as this mechanism is concerned, only the interlock lever associated directly therewith has been shown in the drawings to illustrate its cooperation with the operator mechanism. The cooperation between the lever shown and the door mechanism is well known to those skilled in the art and will be dealt with only briefly in the following description.

With reference to FIGS. 2 and 4, the interlock lever 50 is rotatably mounted at the underside of housing 2 for pivotal movement transversely of the mechanism. A slotted shaft 52, received within a stepped cylindrical recess 2j in housing 2, has a reduced diameter shank extending beyond the underside of housing 2. The extending shank of shaft 52 has opposed flat surfaces formed at the outer end thereof and extends through a correspondingly shaped aperture in the lever 52 to key the lever and shaft together. The end of shaft 50 projecting beyond the lever is riveted over to rigidly secure the lever against the shoulders formed on the shank by the flat surfaces.

As seen particularly in FIG. 4, interlock lever 50 is fonned to have a main body portion extending radially from shaft 52 from which extend a pair of oppositely directed legs 50a and 50b. The leg 50b is provided with a hook portion 50c at the free end and a cam portion 50d at its intermediate portion. A helical tension spring 54 is connected transversely of the mechanism between theside plate 24 and the leg 50b of lever 50 to provide a clockwise rotational bias for the lever as viewed in FIG. 4.

Side piece 38 of the rack assembly is provided with an upstanding tab 38c (FIGS. 4 and 9) which extends into the pivotal path of the hook portion 50b of lever 50. In the switch OFF operating position of the mechanism (FIG. 4) it may be seen that the high point of the cam SM is engaged by the tab 380 to rotate the lever 50 counterclockwise a small amount. Upon movement of the rack assembly toward the right, or switch ON, operating position the lever 50 will rotate clockwise under the bias of spring 54 to cause the hook portion 500 to engage the leading edge of tab 38c and arrest the movement of the rack assembly.

Cover or door assemblies for enclosures utilizing operators of the type disclosed herein are commonly provided with closure handles and linkages which include members that cooperate with the lever 50 of the operator mechanism. As an example the door of an enclosure may be provided with a hook member which, when the door is fully closed, interferes with the leg 50a of lever 50 to arrest the clockwise rotation of the lever (FIG. 4) and thereby hold the hook portion 500 out of the path of tab 38c. In this manner the operator mechanism would be permitted unrestricted movement when the door is closed. The door carried hook member also is designed to extend behind the leg 50a when the lever is abutting the hook to prevent opening the door. Movement of the operator mechanism to the switch OFF position affects return of the rack assembly to the left to cause tab 38c to engage cam 50d and rotate the lever 50 counterclockwise to the position shown in FIG. 4. In this position the leg 50a would clear the hook portion on the door and permit opening the door.

Again referring particularly to FIG. 9, the lower portions of side pieces 36 and 38 may be seen to be offset outwardly of each other. The opposite ends of these lower portions are provided with slots 36d and 38d, respectively, which cooperate in the assembled relation to serve as seats for pins 56. A helical tension spring 58 is connected between the pins 56 to extend longitudinally of the rack assembly in the area between the offset lower portions of the side pieces 36 and 38.

An elongated U-shaped slide member 60 is designed to fit longitudinally within the lower portions of side pieces 36 and 38. The opposite ends of slide 60 have aligned slots 600 which are disposed about the pins 56 in the assembled relationship of the mechanism. In FIG. 2 it may be seen that the spacing between the slots 60a is less than the corresponding spacing between the slots 36d or 38d to afford slide 60 a small amount of free longitudinal movement with respect to the rack assembly.

Slide 60 is further provided with aligned holes 60b in the opposite ends thereof which receive transversely extending axle pins 62 similar to the axle pine 42. The axle pins 62 have reduced diameter outer end portions which extend beyond the sides of slide 60 to receive four rollers 64. The rollers 64 have reduced diameter outer portions which extend within pairs of longitudinally aligned, spaced elongated slots 24b and 26b formed in the side plates 24 and 26, respectively, to mount the slide 60 for longitudinal movement therebetween. The larger diameter portion of rollers 64 lie between the sides of slide 60 and the inner faces of side plates 24 and 26 to space the slide member centrally between the side plates.

The upper surfaces of the legs of U-shaped slide member 60 are provided with elongated grooves 60c formed in transverse alignment with each other and slightly offcenter with respect to the length of the member. Side pieces 36 and 38 of the rack assembly have tabs 36c and 38s, respectively, which are sheared from the lower offset portions thereof and depend coplanar from the upper portions at substantially the longitudinal centers of the pieces. As seen best in FIG. 3, the upper portions of side pieces 36 and 38 and the vertical legs of slide 60 are designed to lie in corresponding vertical planes so that the tabs 36c and 38e are aligned within the grooves 60c of the slide 60.

A rocker plate latch member 66 is assembled within the operator mechanism between the slide 60 and the side plate 24 (see FIG. 3). Rollers 64 provide sufficient space between the latter two members to permit the latch member relatively free movement with respect thereto. The oppositely extending arms of rocker plate 66 are each provided with a headed pin 66 rigidly secured thereto. The shank portions of pins 68 extend through holes formed in the ends of the arms to project beyond the opposite side of the latch member. When assembled in the mechanism, the headed portions of pins 68 extend into rectangular openings 24c in side plate 24 (see FIGS. 1, 3 and 8) to limit the movement of the latch plate. The shank portions of pins 68 extend into a slot 60:1 in slide member 60. A wire spring 70, extending between spacer sleeves 32, bears upon the underside of latch member 66 to urge the latter to its uppermost position as limited by engagement of the shank portions of pins 68 with the upper surface of the slot 60d in slide member 60. The latter surface is also provided with a centrally located groove 6% and the lower surface of side piece 36 of the rack assembly is provided with a pair of oppositely oriented inclined surfaces 36f and 363. The exact cooperation of groove 60c and surfaces 36f and 36g with the latch member 66 will be brought out in the later description of the operation of the mechanism.

The lower, or bight, portion of slide 60 has a plurality of Iongitudinally aligned threaded openings formed therein to receive a pair of screws 72 for securing a drive link 74 to the mechanism. Drive link 74 may comprise various shapes and be positioned at any one of a plurality of positions on the slide 60 with respect to the length thereof according to the type of circuit disconnect device to be controlled and the depth of the enclosure. The general form of the drive link 74 is substantially and L-shaped bracket of which one leg 740 (FIG. 3) is secured to the bight portion of slide 60 and extends laterally therefrom to space the other leg 74b, formed at substantially right angles to the first leg 74a, laterally away from the mechanism. The leg 74b may extend upwardly from leg 74a as shown in the drawings or may depend downwardly therefrom for a relatively deep enclosure, but in either situation, it is desirable to maintain the leg 74b in a plane which is at substantially a right angle with the leg 74a and parallel to the direction of movement. The free end of leg 74b is provided with an elongated slot 740 open to that end for transversely receiving a crank pin or the like on the movable contact assembly of the circuit disconnect device as will be described in connection with FIGS. 10 and l 1.

In applications utilizing a knife switch as the circuit disconnect device, it is desirable to include in the operator mechanism a positive drive means which functions in the OFF to ON direction in the event the switch blades stub against the stationary clips or otherwise resist fully entering the clips. Since it would be an unnatural movement of the handle to back up from the ON operating position to pick up the positive drive feature, it si further desirable that such mechanism be rendered effective prior to the completion of the handle throw, but that it not interfere with the normal snap-action movement of the operator.

The operator mechanism of this invention has incorporated a positive drive linkage which provides the above described features. This linkage includes a lever 76 which is pivotally mounted on the outer surface of side plate 24 by a headed bearing pin 78 (see FIGS. 1, 3, 4 and 8). Pin 78 extends through the side plate 24 from the inner surface thereof and has an annular groove (not shown) in the shank thereof and has an annular groove for receiving a C-clip fastener 30 to retain the lever 76 and pin 78 to the side plate 24. Lever 76 depends along the plate 24 to abut one side of a lateral projection 74d of drive link 74. A drive pin 36c is rigidly secured to side piece 36 of the rack assembly to project outwardly of the mechanism through a longitudinally extending elongated slot 24d in side plate 24. As seen in FIG. 4, pin 360 extends beyond the lever 76 to thereby abut the lever in the OFF to ON direction as will be described later.

In FIGS. 10 and 11 the operator mechanism is depicted in its operating relationship with a knife switch disconnect device mounted within an enclosure. The knife switch is shown in broken lines and only fragments of the enclosure are disclosed. The mechanism is viewed in these FIGS. from an opposite side as had been viewed in the preceding FIGS. and the handle positions therefor appear reversed in FIGS. 10 and l l.

' With reference to the latter FIGS., the operator mechanism is mounted to a front flange 82 of an enclosure by a pair of screws 84 which take into threaded apertures 2k (FIG. 2) formed in the base 2a of housing 2. The knife switch disconnect device 86 is secured to a mounting plate 88 which in turn is mounted within the enclosure and spaced from the rear wall 90 thereof. Knife switch 86 includes a movable contact assembly comprising a plurality of aligned knife blades 92 supported on a carrier 94 which is pivotally mounted on the base of the switch at 26. The blades 92 are pivoted into and out of circuit making engagement with corresponding stationary contact clips 98 by the contact carrier 94 which has a crank arm 100 projecting therefrom at the end of the switch adjacent the operator mechanism. Crank arm 100 carries a transversely extending crank pin 102 which is disposed within the slot 74c of drive link 74 on the operator mechanism. The vertically extending slot 74: with respect to the orientation of the drawings permits the crank pin 102 the necessary vertical displacement due to the arcuate path thereof about the pivot point 96.

OPERATION The operation of the mechanism shown in FIGS. 1-1! will now be described. The operator is shown in FIGS. 1, 2 and 10 in the open circuit, or switch OFF operating position. It is to be assumed herein that the door of the enclosure is fully closed to maintain the hook portion 50c out of the liner path of tab 38:: on the rack assembly of the mechanism.

Rotation of the handle assembly from the OFF position shown in FIGS. 1 and 2 in the direction of the arrow in FIG. 5 causes the rack assembly to be driven to the right with respect to those FIGS. by means of the gears 14 and I6 and toothed rack member 34. Slide 60 is subsequently moved toward the right by virtue of the engagement of the left-hand pin 56 with the slot 600 at the left end of slide 65) to drive the left-hand end of groove 602 thereof against the corresponding pin 6%! of latch member 66. The slide 60 is thereby restrained against further movement while the rack assembly continues toward the right under the control of the handle assembly to the position indicated in FIG. 5.

With reference to FIG. it may be seen that the spring 58 has stretched beyond its normal assembled length due to the separation of the slide and rack assembly and that the inclined surface 36f on side piece 36 of the rack assembly is about to engage the circular end portion of the left-hand arm of latch member 66. Further movement of the rack assembly continues to stretch the spring 5% until the surface lief earns the left-hand end of latch 66 downward to move the shank of that pin 68 out of the grove 611a and release the slide 64 The latter moves rapidly to the right by virtue of the spring 5% and lefthand pin 56 to rotate the movable contact assembly of the switch 86 to the closed position.

The final, switch ON position of the mechanism is shown in FIG. 6 wherein it may be seen that the slide 61) is abutted against the right-hand spacer sleeve 32 and the rack assembly is in its extreme right-hand position as controlled by the handic assembly. The right-hand pin 68 of latch member 66 is now in the groove 60c and the left-hand pin 6% thereof is alatted against the upper surface of slot 6%.

The mechanism is designed to have latch 66 release the slide at a point prior to full travel of the handle assembly. In the event that blades 92 of switch 86 stub against or otherwise fail to fully enter the stationary clips 98, the remaining movement of the handle assembly will cause drive pin 360 of the rack assembly to overtake lever '76, abut the left-hand edge thereof and drive the lever against the projection 74d on drive link 74. Through this connection the blades 92 may be manually forced into the contacts 98.

The operation of the mechanism in the ON to OFF direction is the reverse sequence to that described above. However, the positive drive in this direction is accomplished earlier in the operation and by different members than before described. In FIG. 7 the mechanism is shown in an intermediate position of the ON to OFF direction indicated by the arrow. This position is the reverse of FIG. 5 inasmuch as the surface 36g is about to cam the latch member 66 downward to release the slide 60 for snap movement. It is to be noted that the tab 362, and likewise tab 38a, is approaching the left-hand end of groove 61k in slide 60. The trip point of latch 66 is so designed that if the contacts of switch 86 fail to disengage upon release of the slide 60, the tabs 36c and 382 will abut the end of groove 611:: immediately thereafter to positively drive the slide 611 to the left by the handle assembly. Once the contacts disengage the spring 58 takes over to snap the slide 61 the remaining distance to the OFF position.

MODIFlCATlON The foregoing description has dealt with an operator mechanism for actuating a fused knife switch circuit interrupter which requires a snap action movement to be built into the operator. In certain applications the enclosed circuit interrupter is an automatic circuit breaker which has the quick make and break, or snap-action, feature incorporated within its design as well as an integral operating handle assembly.

The modified operator mechanism shown in FiGS. 12-414 is adapted for use with automatic circuit breakers. The housing, handle assembly; gear drive and interlock lever are identical to the aforedescribed operator and the like parts retain the same reference characters in this description. The side plates 24 and 26 of the previously described mechanism are replaced by side plates 1M and 11116 which contain longitudinally aligned spaced elongated slots idea and Nina, respectively, the slots 1040! being in corresponding transverse alignment with the slots 106a. The side plates Mid and M16 are somewhat shorter in height than the previously described plates 24 and 26 and require only securement to the depending rectangular bosses 2h of housing 2 by rivets 2b to maintain their spaced apart relationship.

Rack member 34 is utilized in this version to which are secured a pair of flat side pieces 108 and 110 by rivets 40. Unlike the side pieces 36 and 38, the lower edges of pieced 108 and 110 are formed in a straight line, devoid of the inclined camming surfaces. Side pieces 108 and 110 are provided with openings aligned with the openings 34b to receive the axle pins 42 therethrough. Three of the rollers 44 are used in this version, the rollers being disposed over the ends of axle pins 42 and within the slots 104a and 1060 of side plates 104 and 106. The fourth roller 112 in this version is similar to the rollers 44 except that it is provided with an outwardly extending conical hub as may be seen in FIG. 14. Thus it may be seen that the rack assembly is mounted for reciprocal longitudinal movement in a manner identical to the previously described operator.

The side piece 110 of the rack assembly is provided with a centrally located upstanding tab 110a which corresponds to the tab We of side piece 38 to cooperate with the interlock lever 51) in the manner aforedescribed. Side pieces 108 and 1 10 are also provided with slots 10% and 11Gb at their respective opposite ends to receive the pins 56 therein. Pins 56 are maintained within the slots 1138b and 11% by the helical tension spring 58 connected therebetween.

Slide member 60 is substituted for in this version by a similar, but less complicated U-shaped slide 114 which has slots 114a formed at its opposite ends for receiving pins 56, the slots 1l4being formed in exact transverse alignment with the slots 108b and 11Gb to eliminate the lost motion travel between the rack assembly and the slide member 114. A drive link 116 is secured to the bight portion of slide 114 by the screws 72, the drive link in this version extending to one side and depending below the mechanism.

While the automatic circuit breaker has not been shown in the drawings, such devices are generally outfitted with a linear slide assembly which is secured over the face of the circuit breaker housing or superstructure. Such slide assemblies have an opening in the movable slide member which is disposed around the handle of the breaker. The slide is further provided with a tab extending to one side of the housing to extend within the slot 116a of drive link 1116 as represented by the dotted lines in FIGS. 12 and 14. While the drive link 1 16 could easily extend laterally to cause the slot 116a to surround the breaker handle directly, such auxiliary slide assemblies are preferrably employed to reduce the effects of adverse tolerance conditions which arise due to the individual operating characteristics of the circuit breakers.

The detent arrangement in the snap-action version earlier described is accomplished in the instant modified version by a helical tension spring 118. A hexagonal screw 120 is turned into a threaded aperture formed in the underside of one of the depending bosses 2h to anchor one end of spring 118 while the other end is hooked around an opposite end of side piece 1 10. Spring 118 thereby urges the mechanism toward its circuit ON operating position. v

To maintain the handle assembly in the OFF position against the bias of spring 118, a leaf spring 122 is secured to the side plate 104 of the mechanism by a pair of screws 124. The spring 122 is spaced from the plate 104 by a pair of flat washers disposed between the spring and side plate and around the screws 124. Spring 122 is formed with an initial bend toward the side plate 104 to urge it to lie flat against the plate. The free end of the spring 122 is offset in a substantially V-shaped portion 122a to serve as a cooperating camming surface for the conical hub of roller 1 12.

As seen in FIG. 12, the handle assembly of the operator mechanism is somewhat extended in the OFF position of the mechanism. This position of the handle assembly is controlled by the engagement of the conical hub of roller 112 with the V- shaped end 122a of spring 122 (FIG. 14). The handle assembly may be moved to its extreme clockwise position which is designed to be a RESET position for the breaker.

with it the channel 114 and drive link 116. The hub of roller 112 cams the end 122a of springl22 away from the side plate 104 as the rack assembly moves to the right.

The circuit breaker mechanism snap or toggles to its ON position at some point in the travel of the rack assembly in the right-hand direction, the handle of the breaker thereafter stopping against an integral stop within the breaker. The final position of the circuit breaker handle controls the final position of the operator mechanism handle assembly by virtue of the nonyielding linkage connections of the circuit breaker handle to the movable slide member, in turn connected to the drive link 116 which is rigidly fastened to slide 114 by screws 72. The detent coil spring 118 urges the rack assembly, and thereby all of the members of the linkage, toward the right against the circuit breaker handle.

Since an entirely rigid connection between the operator handle assembly and the circuit breaker handle could result in damage to the latter if the operator handle is forcibly driven beyond the ON position, a yielding connection is provided between the rack assembly and slide member 114 by spring 58. Movement of the operator handle assembly in either direction beyond the limits of the circuit breaker handle will stretch spring 58 to allow the rack assembly to separate from the slide member 114. Spring 58 returns the rack assembly and the operator handle assembly to the proper position when the force is removed from the handle assembly.

It is to be noted from the foregoing description that the.

modified operator last described basically differs only from the snap-action operator in that the latching, or stored energy function between the rack assembly and the slide have been omitted. The resilient connection between these two members serves as a source of energy for the snap-action version and as an overtravel protective connection in the latter version. While certain parts have been substituted for or changed in the modified version to reduce the manufacturing cost of the operator, the basic design remains the same.

We claim: 1. An operator mechanism for externally actuating a circuit disconnect device housed within an enclosure, said operator mechanism being mounted on a body portion of the enclosure and comprising, in combination:

pivotally mounted handle means extending externally of the enclosure pinion gear drive means operatively connected to said handle means for rotation thereby; rack means linearly driven by said pinion gear means and including a pair of spaced apart side members having transversely aligned slots fonned open to the opposite ends thereof; a pair of transversely extending pins disposed in said aligned slots; spring means connected in tension between said pins to retain said pins in said slots; 7 a slide member mounted for reciprocal movement colinear with said rack means and having a pair of spaced apart side portions each extending along and spaced from respective ones of said side members of said rack means, said slide member side portions having transversely aligned slots formed open to the opposite ends thereof, .said last mentioned aligned slots being disposed about respective ones of said pair of transversely extending pins to provide a resilient connection between said rack means and said slide member, said slide member further including a drive link extending therefrom; and

means connecting the actuating mechanism of said enclosed circuit disconnect device to said drive link wherein linear movement of said drive link in response to movement of said handle means drives said actuating mechanism to cause actuation of said circuit disconnect device. 2. The combination according to claim 1 together with: spring biasedlatch means operable to engage said slide member upon initial movement thereof with said rack means to restrain said slide member from further linear. movement with said rack means, continued movement of v said rack means thereby causing said spring means to be stretched; and Y cam means carried by said rack means to disengage said latch means from said slide member at a predetermined position of said rack means, said spring means restoring to the initial condition thereof upon release of said slide member to rapidly drive said slide member in a direction to overtake said rack means and thereby rapidly actuate said circuit disconnect device.

3. The combination according to claim 2 together with positive drive means operable when said slide member resists movement responsive to the restoring force of said spring means in an unlatched condition of said slide member, said positive drive means operatively connecting said slide member to said rack means ,for direct movement therewith responsive to said handle means.

4. The combination according to claim 3 wherein said positive drive means includes:

a lever pivotally mounted for arcuate movement in a plane parallel to the linear paths of said rack means and said slide member;

a projection on said rack means extending transversely of the path of said lever to abut one side of said lever and directly drive said lever responsive to movement of said handle means; and

a projection on said slide member extending transversely of the path of said lever to be engaged thereby when said slide member resists movement responsive to the restoring force of said spring means in an unlatched condition os said slide member; wherein the normal movement of said slide member maintains the projection thereon ahead of and out of engagement with said lever.

5. The combination according to claim 2 together with:

a lever pivotally mounted for arcuate movement in a plane parallel to the linear paths of said rack means and said slide member;

a pin member secured to said rack means and extending laterally outwardly therefrom transversely of the path of said lever to abut one side of said lever and drive the lever responsive to movement of said handle means;

a tab formed on said drive link to extend laterally outwardly from said slide member and transversely of the path of said lever; and

wherein said lever is driven into abutting engagement with said tab upon'failure of said slide member to overtake said rack means responsive to the aforementioned restoring force of said spring means to cause driving of said slide member directly responsive to movement of said handle means. 

1. An operator mechanism for externally actuating a circuit disconnect device housed within an enclosure, said operator mechanism being mounted on a body portion of the enclosure and comprising, in combination: pivotally mounted handle means extending externally of the enclosure; pinion gear drive means operatively connected to said handle means for rotation thereby; rack means linearly driven by said pinion gear means and including a pair of spaced apart side members having transversely aligned slots formed open to the opposite ends thereof; a pair of transversely extending pins disposed in said aligned slots; spring means connected in tension between said pins to retain said pins in said slots; a slide member mounted for reciprocal movement colinear with said rack means and having a pair of spaced apart side portions each extending along and spaced from respective ones of said side members of said rack means, said slide member side portions having transversely aligned slots formed open to the opposite ends thereof, said last mentioned aligned slots being disposed about respective ones of said pair of transversely extending pins to provide a resilient connection between said rack means and said slide member, said slide member further including a drive link extending therefrom; and means connecting the actuating mechanism of said enclosed circuit disconnect device to said drive link wherein linear movement of said drive link in response to movement of said handle means drives said actuating mechanism to cause actuation of said circuit disconnect device.
 2. The combination according to claim 1 together with: spring biased latch means operable to engage said slide member upon initial movement thereof with said rack means to restrain said slide member from further linear movement with said rack means, continued movement of said rack means thereby causing said spring means to be stretched; and cam means carried by said rack means to disengage said latch means from said slide member at a predetermined position Of said rack means, said spring means restoring to the initial condition thereof upon release of said slide member to rapidly drive said slide member in a direction to overtake said rack means and thereby rapidly actuate said circuit disconnect device.
 3. The combination according to claim 2 together with positive drive means operable when said slide member resists movement responsive to the restoring force of said spring means in an unlatched condition of said slide member, said positive drive means operatively connecting said slide member to said rack means for direct movement therewith responsive to said handle means.
 4. The combination according to claim 3 wherein said positive drive means includes: a lever pivotally mounted for arcuate movement in a plane parallel to the linear paths of said rack means and said slide member; a projection on said rack means extending transversely of the path of said lever to abut one side of said lever and directly drive said lever responsive to movement of said handle means; and a projection on said slide member extending transversely of the path of said lever to be engaged thereby when said slide member resists movement responsive to the restoring force of said spring means in an unlatched condition os said slide member; wherein the normal movement of said slide member maintains the projection thereon ahead of and out of engagement with said lever.
 5. The combination according to claim 2 together with: a lever pivotally mounted for arcuate movement in a plane parallel to the linear paths of said rack means and said slide member; a pin member secured to said rack means and extending laterally outwardly therefrom transversely of the path of said lever to abut one side of said lever and drive the lever responsive to movement of said handle means; a tab formed on said drive link to extend laterally outwardly from said slide member and transversely of the path of said lever; and wherein said lever is driven into abutting engagement with said tab upon failure of said slide member to overtake said rack means responsive to the aforementioned restoring force of said spring means to cause driving of said slide member directly responsive to movement of said handle means. 